How Scala made my tests more meaningful

I have always been interested in improving the way I write and test my systems. Some techniques have been hard to use in languages such as Java. Fortunately Scala with it's power of expression made it much easier. I want to share a few techniques I use on the daily basis.

Transcript

1. How Scala made my tests more meaningful by Piotr Gabryanczyk
2. What is a good test? • easy to write • easy to read and understand • easy to evolve with the system • bang for buck • meaningful
3. Which tests are meaningful? • written using abstractions appropriate for the component you are testing • using vocabulary defined by the API of the component
4. Meaningful test
5. Are integration tests more meaningful?
7. Why is it hard to write integration tests?
8. Why is it hard to write integration tests?
9. Why is it hard to write integration tests?
10. Why is it hard to write integration tests?
11. Hexagonal Architecture
12. Adapters raise the level of abstraction
13. Adapters raise the level of abstraction
14. Fake for every adapter
15. Mixing fake and real adapters
16. Writing fakes is easy - higher order functions
17. Very bad test data
18. Very bad test data
19. Builder Pattern
20. Builder Pattern
21. Builder Pattern
22. It is easy if you build it up gradually
23. It is easy if you build it up gradually
24. Everything depends on everything
25. Peers vs Internals Wikipedia DB Graph Analyzer XML Parser
26. Fewer dependencies Wikipedia DB Graph Analyzer XML Parser DB Adapter Wikipedia Adapter
27. Creating sub- systems is easy!
28. Creating sub- systems is easy!
29. System is a one class with 5 dependencies
30. Creating of the system is easy!
31. Writing integration tests in Scala is Easy!
32. ScalaTest - FreeSpec
33. DSL example
34. Infix notation
35. Implicits
36. Test Labels
37. Test Labels
38. Test Labels
39. Matchers
40. Specs2
41. Expecty
42. ScalaCheck
43. Piotr Gabryanczyk @piotrga piotrga@scala-experts.com